Last week, the Human Connectome Project, supported jointly by sixteen components of the National Institutes of Health, released its first set of data, a massive set of structural and functional images of the brains of sixty-eight adult volunteers—to almost no fanfare whatsoever. The amount of data, two terabytes, is so great that it poses problems for the Internet; you can download it for free if you like, but the organizers of the project would rather mail it to you on a hard drive.

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Fortunately, a study of the thing that the Brain Activity Map seeks to measure—the activity of billions of individual neurons, measured simultaneously—is entirely unprecedented, absolutely necessary, and vastly more fine-grained than the target of the Human Connectome Project. The latter has been looking at the interconnections between roughly five hundred “brain areas”; Obama’s Brain Activity Map is focused on a much more detailed level. The Human Connectome Project is like a plan to figure out broad strokes of the United States economy by mapping the cities that people and goods travel through. The Brain Activity Map is more like an effort to figure out the economy by examining the dynamics of individual consumers. Both projects have value, but their contributions are different, if complementary.